The present invention relates to a variable capacity pump for an internal combustion engine.
A variable capacity pump is well known and used in automotive vehicles. One of them is illustrated on page 182 of a periodical magazine "Motorfan" published in September 1991.
According to this variable capacity pump, a regulator valve has a transfer port connected to a first low pressure pump outlet port, relief ports, an inlet port connected to a second high pressure pump outlet port, and a lubricating oil supply port to the engine. The regulator valve uses a pressure responsive spool formed with an axial passage and a radial passage in order to deliver oil from the inlet port to a pressure chamber. The spool is moveable in response to pressure within the pressure chamber to connect the transfer port to one of the outlet ports or connect the transfer port to the relief port or connect the inlet port to the other relief ports.
An object of the present invention is to provide an alternative to the variable capacity pump.